Apparatus for forming fibrous annular members



Dec. 11, 1956 R. A. BUB

Filed Nov 16, 1954 I l 24 i I 22 mm n I! I 1 57 I l I I I 7 fiaac v x gaa "\a/ 2/129 BY 4 Lil- 311,4 Jada {64 m APPARATUS FOR FORMING FIBROUS ANNULAR MEMBERS Robert A. Bub, Penn Township, Allegheny County, Pa.,

assignor to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Application November 16, 1954, Serial No. 469,253

4 Claims. 01. 92-54 This invention relates to the makingof fibrous annular members, and more particularly to apparatus for forming such members from a slurry of fibers and water. By annular is meant ring-like in any shape, whether circular, square, irregular or otherwise.

Heretofore, fibrous gaskets and similar annular memaxial alignment, generally with one above the other. The side walls of the rings project toward each other, so that the two recesses face each other. The outer walls of the recesses are spaced a considerable distance apart even if the inner walls engage each other. This can be done by making the outer walls shorter than the inner walls, or,

as shown in Fig. 2, by making only one of the inner wall longer than the other three walls.

A pair of annular screens 11 and 12 are disposed between the rings and extend across recesses 5 and 6 and their side walls, to which the screens are secured. The

bers have been made by cutting them from sheets or mats of fibrous material. In some cases the mats are made by drawing fibers onto a screen until a layer of the desired thickness has been deposited. The fibers are carried in water which is drawn through the screen, leaving the fibers against one side of it. Only the side of the mat that engages the screen is perfectly fiat and smooth, and the fibers are packed tightly together so that gaskets cut from the mat have little resiliency.

It is among the objects of this invention to provide apparatus for forming annular members directly from a slurry, which is simple in construction, which forms an annular member completely in finished shape, which produces an annular member with at least two smooth surfaces, and with which annular members of difierent shapes and greatly improved resiliency can be made.

In accordance with this invention a pair of axially spaced rings are provided with opposed annular recesses having inner and outer side walls. A pair of screens are provided between the rings and extend across the recesses and their side walls. Suitable means are provided for holding the two rings together with the screens clamped between the walls at one side of the recess. The

walls at the opposite side of the recesses are spaced much.

farther apart than the walls clamping the screens. The screens in the recesses and between the spaced walls are spaced apart to form a radial chamber in which the annular member is to be formed. The rings are provided without outlet openings adapted to be connected to a source of suction in order to draw a slurry of water and fibers into the radial chamber. The water will be drawn on through the screens and out of the rings, but fibers will be trapped in the chamber to fill it and thereby form an annular member of considerable resiliency.

The invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a plan view of my apparatus with parts broken away;

Fig. 2 is a cross section taken on the line II-II of Fig. 1;

Fig. 3 is a reduced perspective view of an annular member formed in the apparatus; and

Figs. 4 and 5 are views similar to Figs. 2 and 3, respectively, of a modification.

Referring to Figs. 1 and 2 of the drawings, two rings 1 and 2 are shown which have the same internal and external diameters. Each ring has a pair of concentric walls at one side, forming an annular recess between them. Thus, ring 1 has inner and outer walls 3 and 4 forming an annular recess 5, and the other ring has an annular recess 6 between similar inner and outer side walls 7 and 8. When in use, the two rings are placed close together in inner areas of the screens are clamped together between the inner walls of the rings by any suitable means holding the rings together. For example, three C-clamps 13 with thumb screws 14 can be slipped over the rings and tightened to hold them together. With the relative sizes of recess wallsshown in Fig. 2, the upper screen 1 is fiat and engages the lower ends of the upper walls. The inner area of the lower screen engages flat against the upper screen, but the rest of that screen is offset downwardly by providing it with a vertical shoulder 16 spaced only a short distance from inner wall 7. The outer area of the lower screen engages the top of outer wall 8.

Consequently, a radial chamber is formed between the spaced portions of the two screens, with the outer side of the chamber completely open. The thickness or height of the chamber depends on the height of shoulder 16 and the distance between the two outer walls of the recesses. The distance between the outer walls is determined by the thickness that it is desired the annular members formed in this apparatus shall have.

The top of the upper ringand the bottom of the lower ring are provided with outlet openings in which nipples 17 are mounted so that the internal recesses can be connected with tubing (not shown) leading to a suitable source of suction.

The apparatus just described is immersed in a slurry consisting of water and the type of fibers that it is desired to mold into an annular member, such as a gasket 18.

If the gasket is to be employed in high temperature work, mineral wool fibers may be preferred. With the apparatus immersed in the slurry, suction is applied to the rings through nipples l7 and therefore slurry is drawn into the chamber between the two screens. The water will be drawn on through the three perforated walls of the chamber and into the ring recesses, but the fibers will be strained out and trapped in the chamber. Since the fibers are drawn toward three different perforated walls simultaneously, they will not all lie flat in the same general plane as they do when only one screen is used. Instead, they will lie against all three sides of the perforated chamber, with some fibers bent into. the angles between its top and bottom walls and its inner wall 16. The result is similar to folding a fiat mat back on itself, which makes the gasket very resilient and resistant to compression.

Another advantage is that three sides of the gasket have smooth surfaces, the outer side being the only one that is irregular. The density of the gasket can be controlled by the length of time the apparatus is in the slurry and by the amount of suction applied to it. With this method of forming a gasket, its finish, resiliency, hardness, heat resistance, chemical resistance and abrasive resistance also can be controlled.

In the modification shown in Fig. 4, the upper and lower rings 20 and 21 have outer walls 22 and 23, respectively, of equal length and longer than their inner walls 24 and 25 which also are of equal length. The two rings therefore are the same. Consequently, it isthe outer areas of the two annular screens 26 and 27 that are clamped together between the outer walls of the rings. The inner areas of the two screens diverge to form an outwardly tapered chamber between the screens in order to make it clear that annular members can be formed in any desired shape. The upper and lower recesses 28 and 29 are provided with outlet nipples 31 for connection to suction means so that slurry can be drawn into the radial chamber through its open inner side to form a gasket 32 or the like from the slurry fibers. All surfaces of the gasket, except its inside, will be smooth.

According to the provisions of the patent statutes, I have explained the. principle of my invention and have illustrated and described what I now consider to represent itsbest embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I.claim:

1. Apparatus for forming from a slurry of fibers and water an annular member having several smooth sides, comprising a pair of axially spaced rings-provided with opposed annular recesses each having radially spaced inner and outer side walls, a pair of screens between the rings and extending across said recessesand walls, and means for holding the rings together, said screens being clamped between the walls at only one side of the recesses, the walls at the opposite side of the recesses being spaced much farther apart than the clamping walls, the screens in the recesses and between said. spaced walls being spaced apart to form a radial chamber having only one side open, and said rings being provided with outlet openings adapted to be connected to a source of uction to draw slurry into said chamber through the open side,

whereby water will be drawn through the screens and provided with an annular shoulder in one of the recesses spaced 2. short distance from the adjacent clamping wall; 3. Apparatus for forming from a slurry of fibers and water an annular member having several smooth sides,

comprising a pair of axially spaced rings provided with opposed annular recesses each having radially spaced inner and outer side walls, a pair of screens between the 4 rings and extending across said recesses and walls, and means for holding the rings together, said screens being clamped together between only the inner walls of the recesses, said outer walls of the recesses being spaced much farther apart than the inner Walls, the screens in the recesses and between said outer walls being spaced to form a radial chamber having an open outer side only, and said rings being provided with outlet openings adapted to be connected to a source of suction to draw slurry into said chamber through its open side, whereby water will be drawn through the screens and out of the rings, thereby trapping fibers in the chamber to fill it and form said annular member.

4. Apparatus for forming from a slurry of fibers and Water an annular member having several smooth sides, comprising a pair of axially spaced rings provided with opposed annular recesses each having radially spaced inner and outer side walls, a pair of screens between the rings and extending across said recesses and walls, and means for holding the rings together, said screens being clamped together between only said outer walls of the recesses, the inner walls of the recesses being spaced much farther apart than the outer walls, the screens in the recesses and between said inner walls being spaced apart to form a radial chamber having an open inner side only, and said rings being provided with outlet openings adapted to be connected to a source of suction to draw slurry into said chamber through its open side, whereby water will be drawn through the screens and out of the rings and fibers will be trapped in the chamber to fill it and thereby form said annular member.

References Cited in the file of this patent UNITED STATES PATENTS 515,958 Hubbard Mar. 6, 1894 797,122 Kiefer Aug. 15, 1905 827,815 Ormiston Aug. 7, 1906 1,873,585 Harvey Aug. 23, 1932 FOREIGN PATENTS 23,421 Austria Sept. 15, 1905 756,220 France Sept. 18, 1933 

